University of Southern California

USC Neuroscience

Theodore W. Berger


Biomedical Engineering
Viterbi School of Engineering

Research Topics

  1. Learning & Memory

Research Overview

The research of Dr. T.W. Berger involves the complementary use of experimental and theoretical approaches to developing biologically constrained mathematical models of mammalian neural systems. The focus of the majority of currentresearch is the hippocampus, a neural system essential for learning and memory functions. The goal of this research is to address three general issues: (1) the relation between cellular/molecular processes, systems-level functions, and learned behavior; (2) the extent of which the functional dynamics of neural systems are altered by activity-dependent synaptic plasticity; (3) the extent to which the essential functions of a neural system can be incorporated within a hardware representation (e.g., VLSI circuitry).

Experimental studies involve the use of extracellular, intracellular, and whole-cell electrophysiological recording techniques, applied in vivo using anesthetized and chronically implanted animals, and in vitro using hippocampal slice preparations. A number of neurobiological issues are being investigated, including: (1) quantifying the signal processing capabilities of hippocampal neurons and the extent to which these capabilities reflect regulation due to feedforward and feedback circuitry vs. intrinsic neuronal mechanisms, such as voltage-dependent conductances or second messenger biochemical systems; (2) the spatio-temporal distribution of activity in neural networks and its dependence on input pattern and network connectivity; (3) the cellular mechanisms underlying changes in the strength of connections among neurons, i.e., synaptic plasticity, and the influence of synaptic plasticity on signal processing characteristics of neurons and the spatio-temporal distributions of activity in networks.

These and other experimental studies are used in conjunction with several different theoretical approaches to develop models of: (1) the nonlinear, input/output properties of single hippocampal neurons and circuits composed of several populations of hippocampal neurons (in collaboration with Dr. V. Marmarelis, Biomedical Engineering, USC), (2) the hierarchical relationship between synaptic and neuronal events (in collaboration with Dr. G. Chauvet, Institute for Theoretical Biology, University of Angers, France), (3) the kinetic properties of glutamatergic receptor subtypes, and (4) adaptive properties expressed by the "hippocampal-like" neural networks implemented with analog VLSI technology (in collaboration with Dr. B. Sheu, Electrical Engineering, USC).

Contact Information

Web Site:
USC Viterbi
Mailing Address:
1451 UPC
Office Location:
OHE 530D
Office Phone:
(213) 740-8017
(213) 740-0343

Selected Publications

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Lu U,Song D,Berger TW - Nonlinear dynamic modeling of synaptically driven single hippocampal neuron intracellular activity. - IEEE Trans Biomed Eng [2011] May;58(5):1303-13 -PubMed

Berger TW,Hampson RE,Song D,Goonawardena A,Marmarelis VZ,Deadwyler SA - A cortical neural prosthesis for restoring and enhancing memory. - J Neural Eng [2011] Aug;8(4):046017 -PubMed

Hampson RE,Sweatt AJ,Goonawardena AV,Song D,Chan RH,Marmarelis VZ,Berger TW,Deadwyler SA - Memory encoding in hippocampal ensembles is negatively influenced by cannabinoid CB1 receptors. - Behav Pharmacol [2011] Aug;22(4):335-46 -PubMed

Berger TW,Song D,Chan RH,Marmarelis VZ - The Neurobiological Basis of Cognition: Identification by Multi-Input, Multioutput Nonlinear Dynamic Modeling: A method is proposed for measuring and modeling human long-term memory formation by mathematical analysis and computer simulation of nerve-cell dynamics. - Proc IEEE Inst Electr Electron Eng [2010] Mar 4;98(3):356-374 -PubMed

Lu B,Dibazar A,Berger TW - Noise-robust acoustic signature recognition using nonlinear Hebbian learning. - Neural Netw [2010] Dec;23(10):1252-63 -PubMed

Song D,Wang H,Berger TW - Estimating sparse Volterra models using group L1-regularization. - Conf Proc IEEE Eng Med Biol Soc [2010] ;2010():4128-31 -PubMed

Chan RH,Song D,Goonawardena AV,Bough S,Sesay J,Hampson RE,Deadwyler SA,Berger TW - Changes of hippocampal CA3-CA1 population nonlinear dynamics across different training sessions in rats performing a memory-dependent task. - Conf Proc IEEE Eng Med Biol Soc [2010] ;2010():5464-7 -PubMed

Lu U,Song D,Berger TW - Nonlinear dynamic analyses of single hippocampal neurons before and after long-term potentiation. - Conf Proc IEEE Eng Med Biol Soc [2010] ;2010():2762-5 -PubMed

Bouteiller JM,Allam SL,Greget R,Ambert N,Hu EY,Bischoff S,Baudry M,Berger TW - Paired-pulse stimulation at glutamatergic synapses - pre- and postsynaptic components. - Conf Proc IEEE Eng Med Biol Soc [2010] ;2010():787-90 -PubMed

Dibazar AA,Park HO,Berger TW - Nonlinear dynamic modeling of impaired voice. - Conf Proc IEEE Eng Med Biol Soc [2010] ;2010():2770-3 -PubMed